Method and apparatus for producing fibers



4 She'ets-fiheet 2 INVENTOR D. KLEIST IETHOD AND APPARATUS FOR PRODUCINGFIBERS Filed Feb. 12, 1968 1, w fi S fi 5 M L 0 x 2% W v WM b M m ANNA mm 0 0 U Q. w m m ,0 6 1 w A w .Y 3 r. i 2 7 hulllfr M 0 4 w 57 v mun I 6\H/ Dec. 24, 1968 flrmmvgr: v

IBTHOD AND APPARATUS FOR PRODUCING FIBERS Filed Feb. 12, 1968 D. KLEISTDec. 24, 1968 4 Sheets-Sheet 5 INVENTQR 445 A2057 BY m VQ ATTORNEYS Dec.24, 1968 r o. KLEIST 3,418,095

METHOD Ann APPARATUS FOR PRODUCING FIBERS I H 4 Sheets-Sheet 4 FiledFeb. 12, 1968 mgi Y Arraemems I 140 I INVENTOR United States Patent3,418,095 METHOD AND APPARATUS FOR PRODUCING FIBERS Dale Kleist, St.Louisville, Ohio, assignor to Owens- Corning Fiberglas Corporation, acorporation of Delaware Continuation-impart of application Ser. No.499,181, Oct. 21, 1965. This application Feb. 12, 1968, Ser.

14 Claims. c1. 65-5) ABSTRACT OF THE DISCLOSURE This is acontinuation-in-part of application Ser. No. 499,181 filed Oct. 21,1965, now abandoned.

This invention relates to a novel method of and apparatus for formingfibers from heat-softenable materials and more especially to a method ofand apparatus for forming glass fibers from a free falling stream ofmolten glass through the application of forces acting directly on theglass stream for subdividing or disintegrating the glass of the streaminto bodies or primary filaments suitable for attenuation to filamentsby other forces.

One method that has come into extensive use in forming fibers from aglass stream involves the use of a hollow rotor having a peripheral wallperforated with a large number of orifices or openings, the stream beingdelivered into the hollow rotor and under the influence of high speedrotation of the rotor, the molten glass is projected through theorifices of the rotating rotor forming primary filaments or discretelinear bodies projected into an annular attenuating blast wherein theyare attenuated to fine fibers or filaments.

While this method is satisfactory in the commercial production of fibersor filaments for use in producing mats or masses of fibers for variouspurposes, the method necessarily involves the use of a high speed metalrotor operating under extremely high temperature conditions whereby therotor life is comparatively short. The rotor construction iscomparatively expensive as a metal must be employed which is resistantto the high temperatures of themolten glass and the large number oforifices in the peripheral wall of the rotor must be accurately dimensioned and positioned so as not to seriously impair the strength of therotor to resist centrifugal forces or the dynamic balance of the rotor.The primary filaments or individual bodies of glass projected under theinfluence of centrifugal forces from the rotor are subjected to theretarding effect or drag of the ambient air tending to cause the moltenglass to abrade the metal defining the orifices whereby the orificesbecome worn to elliptical shape, thus impairing the formation of primaryfilaments or linear bodies suitable for attenuation to fine fibers.

It has been found that all of the orifices are not worn or abraded tothe same extent and hence primary filaments or bodies of varying sizesare formed, this condition fostering the attenuation of the bodies offibers of nonuniform size.

The present invention relates to a method of forming primary filamentsor discrete linear bodies from a stream 3,418,095 Patented Dec. 24, 1968"ice of molten glass and attenuating the primary filaments to finefibers or filaments without the use of a rotating spinner of rotor orother moving components.

Another bject of the invention resides in a method of subjecting astream of molten material, such as glass, to forces directed generallytangentially of the stream throughout the periphery thereof todisintegrate or subdivide the glass into a large number of primaryfilaments or individual linear bodies which are directed by thetangentially applied forces into an annular gaseous attenuating blastfor continuous attenuation of the primary filaments or bodies to finefibers.

Another object of the invention resides in a method wherein the moltenglass of the stream, during its formation into primary filaments and theattenuation of the primary filaments to fine fibers or filaments, doesnot contact moving components whereby heat losses are reduced to aminimum and without contamination of the glass.

Another object of the invention resides in a method of and apparatus forproducing fine fibers or filaments from a stream of glass of substantialsize enabling the use of low cost, low viscosity glasses.

Another object of the invention embraces a method of forming fibers frommolten glass wherein a stream of molten glass is subdivided into primaryfilaments by the application of forces directed generally tangentiallyinto engagement with the glass stream whereby the primary filaments athigh temperatures are delivered into an attenuating blast with a minimumof heat losses and high fiber yield attained without the use of movingcomponents.

Another object of the invention resides in a relatively stationaryapparatus arranged to accommodate a free falling glass stream andfashioned to direct jets of high velocity fluid into engagement with theglass of the stream for subdividing or disintegrating the stream intoprimary filaments and conveying the primary filaments into an annulargaseous blast for attenuation to fine fibers.

Another object of the invention is the provision of a relativelystationary means fashioned with an internal combustion burner chamber ofannular shape and a passage accommodating a stream of molten glass, thechamber having orifices for delivering high velocity jets of hot gasesof combustion into engagement with the glass of the stream to break upthe glass into individual linear bodies or primary filaments suitablefor blast-attenuation into fine fibers or filaments.

A further object of the invention is the provision of a relativelystationary means or fiberizing unit fashioned with a combustion chamberfrom which high velocity jets of hot gases are delivered in directionstangentially of a glass stream for subdividing the glass of the streaminto linear bodies without the use of mechanical components, andattenuating the projected bodies into fine fibers with a high degree ofenergy efficiency, the fiberizing unit being of compact constructionfacilitating the utilization of a plurality of the units in closelyarranged relation along a glass supply forehearth to attain a highproduction yield of fibers.

Further objects and advantages are within the scope of this inventionsuch as relate to the arrangement, operation and function of the relatedelements of the structure, to various details of construction and tocombinations of parts, elements per se, and to economies of manufactureand numerous other features as will be apparent from a consideration ofthe specification and drawing of a form of the invention, which may bepreferred, in which:

FIGURE 1 is an elevational view showing a group of glass processing orfiber attenuating units of the invention in association with fibercollecting means;

FIGURE 2 is an enlarged sectional view of one of the 3 glass processingand fiber-forming units, the section being taken substantially on theline 22 of FIGURE 3;

FIGURE 3 is a sectional view taken substantially on the line 33 ofFIGURE 2;

FIGURE 4 is a sectional view illustrating a modified form of glassprocessing unit of the invention;

FIGURE 5 is an elevational view of the construction shown in FIGURE 4 inoperative condition;

FIGURE 6 is a vertical sectional view taken substantially on the line6-6 of FIGURE 4;

FIGURE 7 is a top plan view of a modified form of apparatus forprocessing glass;

FIGURE 8 is an enlarged elevational view of one of the components shownin FIGURE 7;

FIGURE 9 is a detail view of a valve means forming a component of theapparatus shown in FIGURE 7, and

FIGURE 10 is a view similar to FIGURE 2 illustrating a modifiedarrangement of the invention.

While the method and apparatus of the invention are particularlyadaptable for processing heat-softenable material, such as heat-softenedglass, in a manner to form primary filaments or linear bodies of theglass of the stream suitable for attenuation to fibers, it is to beunderstood that the method and apparatus may be employed for processingother heat-softened materials.

Referring to the drawings in detail and initially to the arrangementshown in FIGURE 1, there is illustrated a group of glass processing orfiberizing units of the invention arranged to form and deliverattenuated fibers onto a moving collector for forming fibrous mats orother similar products. The arrangement shown in FIGURE 1 is inclusiveof a melting furnace 10 of conventional construction for melting andrefining heat-softenable material, such as glass, a forehearth 12extending from the melting furnace and having a channel 14 receivingheatsoftened and refined glass from the furnace 10 providing a supply ofrefined molten glass for the glass processing units.

In the embodiment illustrated two glass processing units 16 are disposedalong and beneath the floor of the forehearth 12, it being understoodthat a greater number of processing units may be employed if desired.

Disposed beneath and secured to the floor of the fore hearth 12 arestream feeders or bushings 18, there being one feeder 18 for eachprocessing unit, and each feeder receiving molten glass from theforehearth channel through a passage 19.

As hereinafter described, each of the processing units 16 is adapted tosubdivide or break up a glass stream 20 flowing from a feeder 18 intoprimary filaments or discrete linear bodies which are attenuated intofine fibers or filaments by annularly-shaped attenuating blasts. Each ofthe processing units 16 is mounted upon a support member 22 carried by asupporting frame structure 24. Disposed adjacent and beneath eachprocessing unit 16 and supported by the frame structure 24 is an annularmanifold or chamber 26 from which is delivered a high velocity,annularly-shaped blast as hereinafter described which attenuates theprimary filaments or linear bodies delivered from a unit 16 into finefibers or filaments 30.

Supported beneath each blast delivery means or blower 26 is a circularsleeve or shield 32 suspended by members 34 from the frame structure 24.Mounted on each of the sleeves 32 are annular headers or manifolds 36and 37, one manifold being connected with a supply of binder and theother connected with a supply of fluid utilized as a vehicle for thebinder. Disposed circumferentially around the lower end of each sleevemember 32 are nozzles 40 arranged to direct the binder entrained in thefluid vehicle onto the newly formed fibers 30.

The fibers move downwardly under the influence of the attenuating blastsinto a hood or receptacle 42, the fibers being collected in massformation upon the upper flight 46 of an endless belt conveyor 47 of theforaminous or reticulated type. The conveyor 47 is supported by rolls48, one of which is driven by conventional means (not shown). Positionedbeneath the upper flight 46 of the conveyor in registration with theenclosure or hood 42 is a chamber 50 provided by a receptacle 52, thelatter being connected with a suction blower (not shown) by a pipe 54for establishing subatmospheric or reduced pressure in the chamber 50.

The reduced pressure in the chamber 50 assists in the collection of thefibers 30 upon the conveyor flight 46, the reduced pressure conveyingaway the spent gases of the attenuating blasts. The fibers accumulate ina mass 56 which is moved by the conveyor flight 46 beaneth a sizing roll58 which compresses the fibrous mass to a predetermined thicknessproviding a fibrous mat 60. The fibrous mat is conveyed by endless beltconveyor means 61 and 62 through an oven or curing zone 64 in which thebinder or coating on the fibers is cured or set by the application ofheat and circulating air in a conventional manner.

FIGURES 2 and 3 illustrate one form of glass processing means or unitproviding an internal combustion burner producing hot gases for breakingup or subdividing the molten glass of a stream into discrete linearbodies or primary filaments and the bodies or filaments delivered into agaseous attenuating blast.

The unit or combustion burner 16 is inclusive of a substantiallycircular housing means comprising two semicircular portions or sections68 and 70 fashioned of metal. The housing sections 68 and 70 arepivotally joined together by hinge means 72 shown in FIGURE 3, thehousing sections being held in closed or mating position by suitablemeans, such as the latch means illustrated in FIGURE 5 and hereinafterdescribed.

The housing means is comparatively shallow and is provided with a covermeans 74 fashioned of two mating sections, a section being disposed oneach of the semicircular housing sections 68 and 70, each cover sectionbeing secured to its adjacent housing section by screws 76 or othersecuring means. The lower wall regions of the sections comprising thehousing means are fashioned or shaped to provide portions 78 whichtogether form a frusto-conical shape and a second region 80 offrustoconical shape.

Each of the burner housing sections 68 and 70 at their mating Zone isprovided with a metal wall 82 which, in closed or operative positions ofthe housing sections, form a partition means as shown in FIGURE 3. Theinterior walls of the mating housing sections 68 and 70 are lined withrefractory, the lining including refractory 84 at the peripheralinterior, an upper portion of refractory 86 adjacent the cove means 74,a lower refractory portion 88 contiguous with the frusto-conical shapedportions 78, and refractory 90 contiguous with the partitions 82.

Disposed at the central region of the housing means and within thehousing are two semicylindrically-shaped refractory members 92, eachformed with a semicylindrical recess, the recesses together providing apassage 96 through the combustion burner. The cover means 74 and thecentral region of the floor of the housing are formed with semicircularrecesses of the same dimension as the passage 96 whereby the recesses inthe cover means and the housing portions form a continuation of thecylindrically-shaped passage 96 to accommodate the glass stream 20 whichfalls by gravity from a feeder through the central axial region of thepassage 96.

The refractory members 92 and the refractory linings 84, 86, 88 and 90together provide two semiannularlyshaped combustion or burner chambers100 and 102. Each of the chambers 100 and 102 is provided with an inletpipe 104, one of which is shown in FIGURE 2, for conveying combustiblemixture, for example, fuel gas and air into the combustion zones orchambers 100 and 102. The entrance region of the tube 104 into theadjacent combustion chamber is fashioned with a plurality of smallpassages or channels 106 providing a fire screen to prevent ignition ofthe combustible mixture in the inlet tubes 104.

Each of the semiannularly-shaped members 92 is fashioned with aplurality of channels or passages 110 which are downwardly inclinedtoward the longitudinal axis of the passage 96, as shown in FIGURE 2,and are slightly askew with respect to radial axes as shown in FIGURE 3.

The outlets 114 of the passages 110 are preferably arranged in ahorizontal row at the interior cylindrical surface defining the passage96, as shown in FIGURE 2. The entrance regions 116 of the passages 110are flared to facilitate flow of intensely hot gases of combustion fromthe chambers 100 and 102 into the channels 110 to promote a highvelocity for the combustion gases moving through the channels 110 fordelivery from the outlets or orifices 114.

The combustible fuel and air mixture admitted into the chambers 100 and102 through the inlet pipes 104 is ignited and substantially completelyburned within the refractory lined combustion chambers 100 and 102whereby the gases of combustion in the chambers undergo substantialexpansion due to the intense heat so that jets of burned gases ofcombustion move through the channels 110 and are discharged from theorifices 114 at very high velocities.

As shown in FIGURE 3, the passages or channels 110 are arranged askewwith respect to radial axes whereby streams or jets of intensely hotcombustion gases are projected in the direction of the arrows as shownin FIGURE 3 whereby each high velocity jet of gas engages the glassstream at a region spaced from its axis. Through this method ofdirecting the high velocity jets of gases into engagement with the glassof the free falling stream, the forces of the jets or gas streamssubdivided, disintegrate or break up the glass of the stream into linearbodies or primary filaments 120, and the primary filaments delivered bythe velocity of the gases of the jets in the directions indicated inFIGURE 2.

Positioned adjacent the processing unit 16 is an annular blowerconstruction 26 for delivering a high velocity attenuating blast. Theannular blower comprises an annularly-shaped hollow housing 126 and acover 128 providing an annularly-shaped manifold or chamber 130, aninlet means pipe 131 being provided for introducing a fluid, such assteam or compressed air, under pressure into the manifold 130. The coverportion 128 is fashioned with a downwardly extending circular lip orflange 132 which is spaced from a frusto-conical shaped surface 134formed on the housing 126.

The lip 132 is spaced from the surface 134 to provide an annular slot ororifice 136 through which the steam or compressed air from the manifold130 is projected at high velocities providing the attenuating blast. Theregion of the blast delivery orifice 136 is arranged with respect to thepaths of trajectory of the primary filaments or linear bodies 120 ofmolten glass whereby the primary filaments or bodies enter the blastadjacent the blast delivery orifice 136, the high velocity gases of theblast engaging the primary filaments and attenuating them to fine fibers140.

The channels or passages 110 are preferably downwardly inclined, each atan angle of about seventy degrees with respect to the vertical axis ofthe cylindrical chamber 96 as this degree of angularity has been foundeffective to project the primary filaments into the annular highvelocity gaseous blast delivered through the annular slot 136 andattenuated by the blast to fibersv The passages or channels 110 may bedirected downwardly at a slightly more acute angle than seventy degreesbut should preferably not exceed an acute angle less than sixty degreeswith respect to the vertical axis of the chamber 96.

The gases of combustion in the combustion chambers 100 and 102 aredelivered through the channels or passages 110 at linear velocities in arange between forty thousand and sixty-six thousand feet per minute, andpreferably at a velocity of about sixty thousand feet per minuteproviding the high velocity jets for subdividing the glass of the stream20 into primary filaments.

The steam or compressed air from the annular orifice 136, providing thehigh velocity blast engaging the primary filaments 120 and attenuatingthe glass of the filaments to fibers of varying lengths, is deliveredfrom the annular orifice at linear velocities in a range of from fiftythousand and seventy-five thousand feet per minute. It is found that ablast of a linear velocity of about seventy thousand feet per second ispreferred.

A glass composition usable for forming fibers according to the inventionis as follows:

Percent SiO 35 F6203 CaO 18 ZnO 2 The temperature of the above glasscomposition for the stream 20 should be maintained between 2500 F. and2600 F The Viscosity range of the molten glass between the statedtemperatures is 11 poises to 8 poises, and the glass in this viscosityrange has been found satisfactory for forming fibers, the viscositybeing preferably about 10 poises.

Another glass composition usable for forming fibers in the methoddescribed is as follows:

The viscosity range of this glass composition is 18 poises to 3 poisesin a temperature range of 2300 F. to 2700 F. The glass of the stream 20of this composition is most satisfactory for use in the method at atemperature of about 2500 providing a viscosity of about 10 poises andhence of highly liquid character.

In the use of the arrangement shown in FIGURE 1 through 3, a continuousstream 20 of molten glass flows from a feeder 18 associated with theforehearth 12, the stream falling by gravity in the axial region of thepassage 96.

A combustible mixture of fuel gas and air is delivered through the inletpipe 104 under comparatively low pressure and the mixture in thecombustion chambers or burners and 102 is ignited and burnssubstantially completely within the combustion chambers or zones. Themixture is burned under confined conditions in the chambers 100 and 102,the burning gases becoming intensely hot and undergoing expansion in thechambers.

The burned gases or products of combustion, at temperature of 3000 F. ormore, are projected from the chambers through the passages and outlets114 as high velocity jets or streams of gas which engage the moltenglass of the stream and subdivide or break up the glass into primaryfilaments or discrete linear bodies which are delivered by the forces ofthe high velocity jets of gases into the annular attenuating blastdelivered from the blower 26. The filaments or linear bodies 120 areattenuated by the high velocity blast from the blower 26 into finefibers 140. The fibers are collected upon the conveyor flight 46, shownin FIGURE 1, or by other suitable means.

Through this method of processing the glass, the stream of molten glassis subdivided or broken up into primary filaments or discrete linearbodies by the forces of high velocity jets of fluid directed intoengagement with the molten glass and the primary filaments or bodiesdelivered into a gaseous attenuating blast through the use of relativelystationary components, thus eliminating the use of spinners or rotorsfor subdividing the glass into primary filaments.

The use of a stationary combustion burner for developing high velocitystreams of fluid providing the forces for developing the molten glassinto primary filaments requires little maintenance because there are nomoving parts.

Furthermore, the orifices 114 will be maintained of proper size forlonger periods of time without enlargement of distortion. The processingunit 16 is of simple construction and may be manufactured at low cost,thereby substantially reducing the cost of producing attenuated finefibers from primary filaments.

Where steam is used for the attenuating blast delivered from the annularorifice 136, the steam is at a temperature of 400 F. or more, and whenthe blast is compressed air, the air delivered through the orifice 136is at a temperature of about F.

The processing units 16 are compact in size enabling the use of anincreased number of units with a forehearth construction, as shown inFIGURE 1, to provide a high fiber yield for the energy expanded inprocessing the glass.

FIGURES 4 through 6 illustrate another form of apparatus or processingunit for carrying out the method of the invention. In this form theforces utilized in breaking up or subdividing a free falling stream ofglass into linear bodies or primary filaments are provided by highvelocity streams or jets of gas, such as compressed air, wherein the gasmay be preheated to minimize heat losses occurring through the use ofgas streams at temperatures lower than the temperature of the glass. Theapparatus or processing unit includes a generally cylindrically-shapedhousing construction comprising two semicylindrical sections 152 and 154hingedly joined by a hinged means 156 at a mating region of thesections.

A support means or member 153 is welded or otherwise secured to thehousing section 152 for supporting the construction 150. Mounted on thesection 154 at a region diametrically opposite the hinge means 156 is apin 158 upon which is pivoted a manually operable latch member 160, thelatch member 160 having an open slot or recess 162. The housing section152 is provided with a keeper or pin 164 which is received in the slot162 in the manner shown in FIGURE 5 whereby the latch member 160 securesthe housing sections 152 and 154 in closed or normal operative positionas shown.

By swinging the latch member 160 in a clockwise direction, as viewed inFIGURE 5, the latch member may be disengaged from the keeper 164enabling the housing sections to be swung about the hinge means 156 toan open position, as shown in broken lines 154 in FIGURE 4. Extendingacross a diametrical region of the housing section 152 is a metalpartition or plate 168 secured as by welding to the regions 170 of thehousing section 152.

Extending across the diametrical region of the housing section 154 andcontiguous with the metal partition or plate 168 is a metal partition orplate 172 welded or otherwise secured to the regions 174 of section 154.The partition 168 provides, with the housing section 152, a chamber ofsemicylindrical shape, while the partition 172, provides with thehousing section 154, a semicylindrical chamber 178. Disposed concentricwith the axis of the cylindrical housing construction 150 is anannularly-shaped metal wall construction fashioned of two semiannularlyshaped sections 182 and 184.

The semiannularly shaped section 182 is joined by welding to thepartition or plate 168, and the section 184 likewise joined by weldingto the partition or plate 172. The interior cylindrical region definedby the two semiannularly shaped sections 182 and 184 provides a walledpassage 188 similar to the passage 96, shown in FIGURE 2, the passage 188 accommodating a free falling glass stream 26' substantially alignedwith the central axis of the passage 188. Mounted upon the housingsection 152 is a semicircular cover or plate 192 secured by screws 194.

Mounted on the housing section 154 is a similar cover or plate 196secured by screws 198. The cover plates 192 and 196 are equipped withsemicircular recesses 200 which mate to form a circular opening toaccommodate a tenon construction 202 provided on the semiannularsections 182 and 184, as shown in FIGURE 6. Secured to the housingsection 152 is a threaded bushing 204 registering with an opening 206 inthe wall of the housing section 152, the bushing 204 accommodating apipe 208, shown in FIG- URE 6, connected with a supply of gas underpressure for delivery into the chamber 176.

The housing section 154 is equipped with a threaded bushing 210registering with an opening 212 in the housing wall, the bushing 210accommodating a pipe (not shown) of the character shown at 208 in FIGURE6, adapted to be connected with a supply of gas under pressure. Valvemeans (not shown) of conventional construction are provided for theinlet pipes for controlling flow of gas under pressure into the chambers176 and 178.

The bottom wall regions of the housing sections 152 and 154 arefashioned with semicircular boss portions 214 and 216 which mate withthe semiannular sections 182 and 18 as shown in FIGURE 6. The interiorof the hollow configuration provided by the bosses 214 and 216 isdefined by semifrusto-conical surfaces 218 which together, provide afrusto-conical shaped passage 220 forming a continuation of the passage188. The boss portions 214 and 216 are each provided with acomparatively large number of small gas passages or channels 222 incommunication with the chambers 176 and 178, the outlets or orifices 224of the channels opening into the passage 220.

The axes of the channels 222 are angularly inclined slightly downwardlyas indicated by the arrows 226 at angles of about seventy degrees withrespect to the vertical axis of the cylindrical passage 188. The arrowsindicating the paths of travel of gas streams delivered from theorifices 224. The axes of the channels 222 are preferably normal to thetaper of the surface 218 defining the frusto-conical shaped passage 220.As shown in FIGURE 4, the channels 222 are slightly askew with respectto radial axes and are generally tangential with respect to the glassstream 20 descending through the passage 188.

The gas streams at high velocities, delivered through the channels 222in the direction of the arrows 230, impinge the glass stream at regionsspaced from its axis and break up the glass of the stream into linearbodies or primary filaments which are entrained and projected by theforces of the gas streams along the paths 226 indicated by the arrows inFIGURE 6.

The streams or jets of gas entrain and convey the linear bodies orprimary filaments of glass into an annularlyshaped gaseous blast from ablower of the character shown at 26 in FIGURE 2, employed with thearrangement shown in FIGURES 4 through 6. The annular blast attenuatesthe discrete linear bodies or primary filaments of glass to fine fibersin the same manner as described in connection with the form of apparatusshown in FIG- URE 2.

The gas supplied to the manifolds or chambers 176 and 17 8 may becompressed air, and the air may be preheated prior to its delivery intothe chambers 176 and 178 so that the high velocity streams of heated airfrom the out lets or nozzles 224 minimizes heat losses from the primaryfilaments. The velocity of the air streams delivered from the passages222 should be in a range of from fifty thoussand to seventy thousandfeet per minute and preferably nearer seventy thousand feet per minute.

The semiannularly shaped sections 182 and 184 defining I the walledpassage 188 may be of porous metal whereby some air from chambers 176and 178 may pass or filter through the pores in the metal to minimizethe liability of the molten glass to stick or adhere to the wallsdefining the passage 188 in the event that the glass stream shouldmomentarily deviate from its normal flow path at the axial region of thepassage 188.

FIGURES 7 through 9 illustrate another form of apparatus for breaking upor subdividing the glass of a free falling glass stream into discretebodies or primary filaments by high velocity gas streams delivered fromindividual nozzles circumferentially disposed about the axis of thestream of glass.

With particular reference to FIGURE 7, the apparatus includes a circularsupport frame construction 250 comprising two mating semiannular framesections 252 and 254 preferably of L-shaped cross section, the sectionsbeing hinged together by hinge means 256 to effect relative movementbetween the frame sections 252 and 254 to facilitate access formaintenance.

The opposite ends of the frame sections are in mating relation as shownat region 258 and may be held together by latch means (not shown)similar to that illustrated in FIGURE 5. Welded or otherwise secured tothe inner surfaces of the frame sections are inwardly projecting supportmembers or means 260. Adjustably mounted on each of the inwardlyextending members 260 is a nozzle construction 262 having a nozzleoutlet 264 through which gas under pressure is projected as a highvelocity gas stream.

Each gas stream is projected in a path to impinge the glass of thestream 20" and break up or subdivide the glass into discrete linearbodies or primary filaments. The filaments or bodies are entrained bythe gas streams and delivered thereby into an annular blast from anannular manifold of the character shown at 26 in FIGURE 2 to attenuatethe bodies or primary filaments to fine fibers by blast attenuation.

As particularly shown in FIGURE 8, each of the nozzle constructions isequipped with a member 266 fashioned with a slot 267 adapted toaccommodate a winged bolt 268 which is threaded into an opening in themember 260.

By manipulating the winged bolt 268, the nozzle construction 262 may beadjusted to modify the angularity of impingement of the gas streamsagainst the glass of the free falling stream to properly direct theprimary filaments into an annular attenuating blast.

In this form of apparatus, air or other gas under pressure is deliveredthrough tubes 270 from a distributing means or plate 272 mounted on ahousing 274 which is secured to or associated with an electricallyenergizable motor 276 spaced from the assembly of nozzles 262. Thehollow housing 274 defines a chamber 278 which receives air or other gasthrough an inlet tube 280 which is connected with a supply of compressedair or other gas. Disposed within the chamber 278 and in contiguousrelation with the inner surface of the distributing plate 272 is a valvemeans or valve disc 282, shown in FIGURE 9, fixedly secured on the motorshaft 284.

The valve member or valve disc 282 is provided with open areas or slots285 and 286, preferably of different lengths, defined by bridge portions288. The valve disc 282 is rotated by the motor 276 and cooperates withoutlets 290 in the distributor plate 272 connected with the tubes 270for intermittently obstructing flow of compressed air through openings290 and tubes 270 successively to the nozzle constructions 262. Thevelocity of the jets of air from the nozzles 264 should be as high aspracticable and preferably upwards of fifty thousand feet per minute.

Through the use of the rotating valve disc or member 282, the airdelivered to the nozzles 262 is momentarily interrupted to each of thenozzles in sequence as an assist in disrupting or breaking up the glassof the stream into streamlets or primary filaments conveyed by the gasstreams into an annular attenuating blast.

FIGURE 10 illustrates a fiber-forming means or unit of the invention inassociation with a burner or heat applying means for delivering heatonto the discrete bodies or primary filaments during their traverse fromthe stream disrupting region into the annular attenuating blast forreducing heat losses from the bodies or primary filaments The means fordisrupting the glass of the stream 20' to form the primaries 120' may beof the character illustrated at 16 in FIGURE 2, or the constructionshown at 150 in FIGURE 4, or the arrangement illustrated at 250 inFIGURE 7.

The primary filaments or discrete linear bodies 120' are projected intoa high velocity attenuating blast delivered from a blower 26' of thecharacter shown at 26 in FIGURE 2, the high velocity gaseous blast fromthe blower engaging the primary filaments 120' for attenuating theprimary filaments into fine fibers Surrounding the unit 16 is anannularly-shaped housing or casing 300 which is of hollow configurationproviding a manifold chamber 302 adapted to contain a combustiblemixture such as fuel gas and air, the mixture being admitted into themanifold chamber 302 from a supply through one or more inlet pipes 304.

The bottom wall of the manifold housing 300 includes an orifice plate306 preferably fashioned with a plurality of concentrically arrangedcircular ledges 308 forming an echelon configuration. The orifice plate306 is provided with a plurality of rows of passageways or channels 310,the channels being of comparatively small diameters.

The fuel and air mixture in the chamber 302 is under comparatively lowpressure and the mixture flows downwardly through the channels 310, themixture being ignited and burned adjacent the primary filaments orprim-aries 120'.

As the mixture conveying passageways 310 are of small size, ignition ofthe combustible mixture does not occur in the manifold chamber 302.Through this arrangement the primaries 120 are subjected to heat fromthe burner thus reducing heat losses from the primary filaments duringtheir traverse toward the attenuating blast from the blower 26'.

Through the arrangement and method of the invention, the glass of a freefalling stream is effectively disrupted and subdivided into primaryfilaments or discrete streamlets eliminating the use of a rotor meansfor converting or reducing a glass stream to primary filaments. Therelatively static fiber-forming units hereinabove described are ofcompact construction, facilitating the use of several units arranged inadjacent relation each delivering fibers into a collecting zone in themanner show in FIGURE 1.

Thus, a substantial amount of molten glass may be processed per unit oftime and thereby attain a high fiber yield from glass supplied by asingle forehearth to several fiber forming units.

It is apparent that, within the scope of the invention, modificationsand different arrangements may be made other than as herein disclosed,and the present disclosure is illustrative merely, the inventioncomprehending all variations thereof.

I claim:

1. The method of forming fibers of heat-softened mineral materialincluding flowing a stream of the material from a supply, deliveringhigh velocity streams of gas from regions circumferentially of thematerial stream into engagement with the material to break up thematerial into a plurality of primary filaments, conveying the primaryfilaments substantially radially outwardly from the axis of the streamof material by the forces of the gas streams, engaging the primaryfilaments with an annular blast of gases moving at high velocities, andattenuating the primary filaments to fibers by the forces of the blast.

2. The method according to claim 1 including burning combustible mixtureunder confined conditions, and delivering the gases of combustion as thehigh velocity streams of gas.

3. The method according to claim 1 wherein the mineral material isglass.

4. The method according to claim '1 including applying heat to theprimary filaments prior to engaging the primary filaments with theannular gaseous blast.

5. The method of forming fibers from heat-softened glass includingflowing a stream of the glass in a vertical path from a supply at atemperature wherein the viscosity of the glass of the stream is within arange between three poises and eighteen poises, projecting high velocitygas streams from regions circumferentially of the stream into engagementwith the glass of the stream to disrupt the glass into a plurality ofprimary filaments, conveying the 'primary filaments substantiallyradially outwardly from the axis of the glass stream by the forces ofthe gas streams, engaging the primary filaments with an annular highvelocity gaseous blast, and attenuating the primary filaments intofibers by the forces of the blast.

6. The method according to claim 5 wherein combustible mixture of fueland air is substantially completely burned within a confined zone andthe gases of combustion delivered through orifices providing the highvelocity gas streams.

7. The method according to claim 5 wherein the glass of the stream is ofa viscosity in a range between eight poises and eleven poises.

8. The method of claim 5 wherein each of the high velocity gas streamsis directed downwardly at an angle of substantially seventy degrees withrespect to the glass stream.

9. The method of forming fibers from heat-softened glass includingestablishing a free falling stream of glass of a viscosity in a rangebetween three poises and eighteen poises, directing high velocity gasstreams from regions circumferentially of the glass stream toward theglass stream, impinging the gas streams with the glass at regions spacedfrom the axis of the glass stream, disrupting the glass into a pluralityof primary filaments by the forces of the gas streams, conveying theprimary filaments by the gas streams substantially radially outwardlyfrom the glass stream, engaging the outwardly moving primary filamentswith an annular high velocity gaseous blast with the gases of the blastmoving in paths substantially parallel with the axis of the glassstream, and attenuating the primary filaments to fibers by the forces ofthe gases of the blast.

'10. The method according to claim 9 wherein each of the gas streams isdirected downwardly at an angle not greater than seventy degrees withrespect to the axis of the glass stream.

11. The method according to claim 9 including applying heat to theprimary filaments prior to their engagement with the gases of theannular blast.

12. Apparatus of the character disclosed, in combination, meansproviding an annularly shaped chamber for producing high velocity gasesand a central, vertically walled passage with means to feed a stream ofheatsoftened glass from a supply through said passage, the wall definingthe passage having a plurality of circumferentially arranged channels incommunication with the chamber, means for delivering gas under pressureto said passage from outlets of the channels for projection from theoutlets as high velocity gas streams, each of said channels beingdisposed to direct the gas streams into engagement with the stream ofheat-softened glass at a region spaced from the axis of the glass streamto form primary filaments of the glass, and means providing a highvelocity annular gaseous blast engaging the primary filaments forattenuating the filaments to fine fibers.

13. The combination according to claim 12 including heating meanssurrounding the chamber for applying heat to the primary filaments.

14. The combination of claim 12 wherein each of the channels is inclineddownwardly at an angle of about seventy degrees with respect to the axisof the glass stream.

References Cited UNITED STATES PATENTS 3,282,668 11/1966 Mabra 65-53,340,334 9/1967 Feldmann et al. 26412 3,357,808 12/1967 Eberle 6516FOREIGN PATENTS 928,865 6/ 1963 Great Britain. 1,017,516 10/1957Germany.

DONALL H. SYLVESTER, Primary Examiner.

R. L. LINDSAY, JR., Assistant Examiner.

U.S. Cl. X.R.

